Clinical outcome of microscopic lumbar spinous process-splitting laminectomy: clinical article

OBJECT

The authors sought to quantify the clinical outcome of microscopic lumbar spinous process-splitting laminectomy in patients with lumbar spinal stenosis (LSS). They performed a microscopic laminectomy in which the spinous process is split longitudinally into 2 halves. For single-level decompression, they inserted a tubular retractor between the split process.

METHODS

Data obtained in a total of 124 patients were retrospectively analyzed. Patients were divided into 2 groups: the "slip" group, comprising patients with spondylolisthesis-type LSS with vertebral body slippage (Group 1), and the "nonslip" group, comprising patients with spondylosis-type LSS without vertebral body slippage or with LSS due to central protrusion of lumbar disc herniation. Clinical outcome in all patients was evaluated by using the Japanese Orthopaedic Association score. In the slip group, slippage and instability rates were evaluated by using pre- and postoperative dynamic radiographs in the sagittal plane. Postoperative CT images were used to evaluate bony union at 2 sites: a region between the left and right portions of the halved spinous process and a region between the base of the halved process and vertebral arch. Signal intensity of the multifidus muscle at individual decompression levels was evaluated on pre- and postoperative T1- and T2-weighted MR images.

RESULTS

Preoperative clinical symptoms improved significantly after surgery in all patients. Slippage and instability rates in the slip group showed no significant differences when pre- and postoperative conditions were compared. Union rates at the region between the left and right portions of the halved process and the region between the base of the halved process and vertebral arch were 97.1% and 82.5%, respectively. Magnetic resonance imaging showed only a small amount of fat infiltration in the multifidus muscle after surgery in 12.2% of cases.

CONCLUSIONS

The authors recommend microscopic lumbar spinous process-splitting laminectomy as a promising minimally invasive surgery for the treatment of LSS.

Contribution of plasma proteins, albumin and alpha 1-acid glycoprotein, to pharmacokinetics of a multi-targeted receptor tyrosine kinase inhibitor, sunitinib, in analbuminemic rats

The present study investigated the role of the major plasma proteins, albumin and α1-acid glycoprotein (AAG), in the pharmacokinetics of sunitinib using Sprague-Dawley (SD) rats and analbuminemic rats with considerably low concentration of albumin established from SD rats. When sunitinib (3 mg/kg) was administered intravenously, the plasma concentrations of sunitinib at the early-distribution phase were significantly lower in analbuminemic rats than those in SD rats. The corresponding pharmacokinetic parameters of systemic clearance and volume of distribution at steady-state of sunitinib were significantly larger in analbuminemic rats (2.17 l/h/kg and 3.94 l/kg, respectively) than those in SD rats (1.26 l/h/kg and 2.37 l/kg, respectively). In in vitro protein-binding experiments using an equilibrium dialysis method, the binding profiles of sunitinib in SD and analbuminemic rats were linear, and the unbound fraction in analbuminemic rats (0.110) was significantly larger than that of SD rats (0.062). However, no significant differences in the unbound plasma concentration-time curves and pharmacokinetic parameters of sunitinib were observed between SD and analbuminemic rats. Protein-binding profiles of sunitinib to human serum albumin and AAG showed concentration independency and the binding potency was 65.3% and 33.7%, respectively. These results suggest that AAG has a low affinity for sunitinib and that the contribution of AAG to plasma protein-binding of sunitinib is relatively low compared to albumin. The present study suggests that the increased systemic clearance of sunitinib in analbuminemic rats might be due to an increase in the volume of distribution at steady-state, which could be due to the significant increase in the unbound fraction of sunitinib due to the low concentration of albumin.

Fear extinction requires Arc/Arg3.1 expression in the basolateral amygdala

Background

Prolonged re-exposure to a fear-eliciting cue in the absence of an aversive event extinguishes the fear response to the cue, and has been clinically used as an exposure therapy. Arc (also known as Arg3.1) is implicated in synaptic and experience-dependent plasticity. Arc is regulated by the transcription factor cAMP response element binding protein, which is upregulated with and necessary for fear extinction. Because Arc expression is also activated with fear extinction, we hypothesized that Arc expression is required for fear extinction.

Findings

Extinction training increased the proportion of Arc-labeled cells in the basolateral amygdala (BLA). Arc was transcribed during latter part of extinction training, which is possibly associated with fear extinction, as well as former part of extinction training. Intra-BLA infusions of Arc antisense oligodeoxynucleotide (ODN) before extinction training impaired long-term but not short-term extinction memory. Intra-BLA infusions of Arc antisense ODN 3 h after extinction training had no effect on fear extinction.

Conclusion

Our findings demonstrate that Arc is required for long-term extinction of conditioned fear and contribute to the understanding of extinction as a therapeutic manner.

A non-invasive biomonitoring method for assessing levels of urinary pyrethroid metabolites in diapered children by gas chromatography-mass spectrometry

The aim of this study was to develop a method for quantitative measurement of urinary metabolites of pyrethroid (PYR) insecticides, trans-chrysanthemumdicarboxylic acid (CDCA) and 3-phenoxybenzoic acid (3-PBA), extracted from disposable diapers. This study was approved by the university ethics committees, and informed consent was obtained from all the parents for their children and from adult volunteers. After extraction of PYR metabolites in the absorber of diapers with 5 ml acetone, the metabolites in the eluents were extracted with tert-butyl methyl ether, derivatized with 1,1,1,3,3,3-hexafluoroisopropanol and analyzed by gas chromatography-mass spectrometry. The limits of quantitation (LOQs) were 0.55 μg/l for CDCA and 0.09 μg/l for 3-PBA in 2 ml urine extracted from diapers. Within-series and between-day precisions were <14% (CV%) over the concentration range of metabolites from 0.4 to 20.4 μg/l urine. When concentrations of each metabolite were measured with the developed method after pouring 2 ml urine, which was obtained from adults both in a general population and pest control operators, on diapers, good correlations were shown between the measured results and the concentrations measured directly for the respective urine with the conventional method (Spearman's rank correlation coefficient 0.889 for CDCA and 0.989 for 3-PBA; n=27-28). The developed method would be applicable to epidemiological studies.

Importance of platinum-free interval in second-line chemotherapy for advanced or recurrent endometrial cancer

PURPOSE

To investigate the effectiveness of platinum-based combination chemotherapy as second-line chemotherapy for patients with advanced or recurrent endometrial cancer treated initially by platinum-based combination chemotherapy.

MATERIALS AND METHODS

Subjects were patients who had received platinum-based combination chemotherapy as second-line chemotherapy: 56 patients with recurrent disease who had previously received postoperative adjuvant platinum-based combination chemotherapy (Category 1) and 21 patients who had received first-line chemotherapy but not adjuvant chemotherapy for advanced or recurrent disease (Category 2). Patients' records were searched for the response to second-line chemotherapy and survival, particularly in relation to the platinum-free interval (PFI).

RESULTS

APFI over 12 months was a predictor of response (64.7%) and overall survival time (23 months) in Category 1 patients. A PFI of less than three months was a negative predictor of response (0%) and overall survival (nine months) in Category 2 patients.

CONCLUSION

Platinum-based combination chemotherapy appears to be effective as second-line chemotherapy for endometrial cancer if the PFI is sufficiently long.

Telaprevir-based triple therapy for chronic hepatitis C patients with advanced fibrosis: a prospective clinical study

BACKGROUND

Antiviral treatment is recommended for chronic hepatitis C patients with advanced fibrosis to reduce and prevent cirrhosis-related complications.

AIM

To evaluate the efficacy and safety of telaprevir (TVR)-based triple therapy for patients with advanced fibrosis in a clinical practice setting.

METHODS

This prospective, multicentre study consisted of 102 patients with advanced fibrosis (METAVIR score F3-4) who were infected with HCV genotype 1b. All received 12 weeks of TVR in combination with 24 weeks of pegylated interferon (PEG-IFN) α2b and ribavirin (RBV).

RESULTS

The sustained virological response (SVR) rate was 69.6% (71 of 102). Notably, for treatment-naïve and prior relapse patients the SVR rate was over 80%. Previous treatment response, interleukin 28B polymorphism (rs8099917) and rapid virological response (undetectable HCV RNA at week 4) were independently associated with SVR. To achieve SVR, an adequate dosage of PEG-IFNα2b (≥1.2 μg/kg/week) and RBV (≥7.5 mg/kg/day) is preferable; however, the mean weight-adjusted TVR dosage had little impact on treatment outcome. Although severe blood cytopaenia and a dermatological disorder were frequently found, the rate of discontinuation due to adverse effects was 12.7%. The inosine triphosphatase CC allele (rs1127354) was independently associated with the development of severe anaemia, and lower serum albumin level (<35 g/L) was associated with the occurrence of infection.

CONCLUSIONS

The great gain in the SVR rate by telaprevir-based triple therapy offsets the problems with adverse effects; thus, it should be considered as a potent treatment protocol for patients with advanced fibrosis, especially for those with treatment-naïve and prior relapse.

Anti-interleukin-6 receptor antibody reduces neuropathic pain following spinal cord injury in mice

The present study reports the beneficial effects of an anti-mouse interleukin-6 (IL-6) receptor antibody (MR16-1) on neuropathic pain in mice with spinal cord injury (SCI). Following laminectomy, contusion SCI models were produced using an Infinite Horizon (IH)-impactor. MR16-1 was continuously injected for 14 days using Alzet osmotic pumps. A mouse IL-6 ELISA kit was then used to analyze IL-6 levels in the spinal cord tissue between 12 and 72 h after injury. Motor and sensory functions were evaluated each week using the Basso Mouse Scale (BMS), plantar von Frey and thermal threshold tests. Histological examinations were performed 42 days after SCI. Between 24 and 72 h after SCI, the expression levels of IL-6 were significantly decreased in the MR16-1 treated group. Six weeks after surgery, the BMS score of the MR16-1-treated group indicated significant recovery of neurological functions. MR16-1-treated mice in the SCI group exhibited lower paw withdrawal thresholds in the plantar von Frey and thermal tests, which were used to evaluate allodynia. MR16-1 treatment significantly increased the area of Luxol fast blue-stained tissue, representing spared myelin sheaths. These results indicate that the continuous inhibition of IL-6 signaling by MR16-1 between the early and sub-acute phases following SCI leads to neurological recovery and the suppression of hyperalgesia and allodynia. Overall, our data suggest that the inhibition of severe inflammation may be a promising neuroprotective approach to limit secondary injury following SCI and that an anti-IL-6 receptor antibody may have clinical potential for the treatment of SCI.

Drug interaction between sunitinib and cimetidine and contribution of the efflux transporter ATP-binding cassette C2 to biliary excretion of sunitinib in rats

The present study investigated the effect of the H2 antagonist cimetidine on the pharmacokinetics of a multi-targeted receptor tyrosine kinase (RTK) inhibitor, sunitinib, in Sprague-Dawley (SD) rats and Eisai hyperbilirubinemic mutant rats (EHBR) lacking the efflux transporter, ATP-binding cassette C2 protein (ABCC2). Rats received an intraperitoneal injection of cimetidine (10 mg/kg) once a day for three days. On day 4, sunitinib (3 mg/kg) was administered intravenously 30 min after the final injection of cimetidine or saline to SD rats. Disappearance of sunitinib from plasma was significantly delayed by cimetidine. The pharmacokinetic parameter of sunitinib, systemic clearance (CLSYS), was significantly reduced and the half-life was significantly prolonged, with no change in the volume of distribution at steady-state (VSS). When the effect of cimetidine on the biliary excretion of sunitinib at steady-state condition was investigated in SD rats, cimetidine had no effect on some transporter-mediated biliary excretion of sunitinib. Furthermore, the contribution of ABCC2 to the biliary excretion of sunitinib was also examined in SD rats and EHBR. The biliary clearance of sunitinib was significantly lower in EHBR, but the biliary excretion rate of EHBR was not different from that of SD rats, and the contribution of biliary excretion to systemic elimination was small, suggesting that sunitinib is mainly eliminated by cytochrome P450 3A4 (CYP3A4)-mediated metabolism and is not excreted into the bile via ABCC2. These findings indicate that co-administration of cimetidine alters the pharmacokinetics of sunitinib probably due to inhibition of CYP3A4, suggesting the possibility that cimetidine should be used carefully for patients with cancer being treated with sunitinib therapy.

[Mechanisms of memory bridging past and present]

The human mind develops through history within the passing of time. Thus, what determines the passing of time in the human mind? For example, when you are asked about yourself 10 years before now, you are able to answer by tracing back through your own experiences. You will be confident of your answer as far as you rely on your memory. Therefore, your personal memory is critical for the passage of time; however, how memory that allows for mental time travel is formed or maintained in the brain is largely unknown. This type of memory may exist only in humans. In this article, we review past studies on memories that emerge from time information in human and experimental animals.

Observation of the (Λ)(7)He hypernucleus by the (e, e'K+) reaction

An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, (Λ)(7)He, was observed for the first time with the (e, e'K+) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The (Λ)(7)He binding energy supplies the last missing information of the A = 7, T = 1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.

Impact of multimodal therapy on the survival of patients with newly diagnosed uterine carcinosarcoma

PURPOSE

To investigate treatment outcomes of uterine carcinosarcoma (CS) patients who underwent complete surgical resection of all visible disease and platinum-based adjuvant chemotherapy (multimodal therapy).

MATERIALS AND METHODS

The authors reviewed 127 uterine CS patients treated at this institution from 1990 to 2010. They operated 123 patients in clinical Stages 1-3, 97 of which underwent complete resection and systemic lymphadenectomy.

RESULTS

A total of 97 patients (FIGO 2008: Stage 1 in 50 patients, Stage 2 in six, Stage 3 in 37, and Stage 4 in four) underwent surgical staging, 74 of which were administered five cycles (median) of platinum-based adjuvant chemotherapy. The median overall survival (OS) associated with multimodal therapy 50.6 months compared with 34.9 months incomplete multimodal therapy. After multimodal treatment, 32.9% (32/97) patients showed recurrence (24/32 hematogenous).

CONCLUSION

Multimodal therapy increased survival among uterine CS patients, but the recurrence rate remained high. Further consideration of treatment options for uterine CS is required.

Population activity in the dorsal hippocampal CA1 encoding the surrounding environment is absent during contextual fear memory expression

The hippocampus plays a critical role in contextual fear conditioning. Population activity in the hippocampal CA1 encoding the surrounding environment is thought to be responsible for retrieval of contextual fear memory. However, the characteristics of CA1 neuronal ensemble activity during retrieval of contextual fear memory remain unclear. Here, we examined CA1 ensemble activity during contextual fear memory expression in male C57Bl/6J mice, using Arc cellular compartment analysis of temporal activity by fluorescence in situ hybridization. The "Shock" group was conditioned with a footshock in two separate chambers, whereas the "No shock" group was not exposed to shocks in the chamber. Animals were then re-exposed to either the same chamber twice or two different conditioning chambers. In the No shock group, exposure to the same chamber twice activated a more significantly overlapping neuronal population than exposure to two different chambers. In the Shock group, exposure to the same conditioning chamber twice activated a similarly overlapping neuronal population as exposure to two different chambers, with overlap smaller than in nonshocked mice exposed to the same chamber twice. Thus, population activity in the hippocampal CA1 encoding the surrounding environment is detected during spatial exploration, but absent during contextual fear memory expression. Even the variable ensemble activity of CA1 may contribute to retrieval of contextual fear memory.

Differential calcium dependence in basal and forskolin-potentiated spontaneous transmitter release in basolateral amygdala neurons

Action potential-independent transmitter release, or spontaneous release, is postulated to produce multiple postsynaptic effects (e.g., maintenance of dendritic spines and suppression of local dendritic protein synthesis). Potentiation of spontaneous release may contribute to the precise modulation of synaptic function. However, the expression mechanism underlying potentiated spontaneous release remains unclear. In this study, we investigated the involvement of extracellular and intracellular calcium in basal and potentiated spontaneous release. Miniature excitatory postsynaptic currents (mEPSCs) of the basolateral amygdala neurons in acute brain slices were recorded. Forskolin, an adenylate cyclase activator, increased mEPSC frequency, and the increase lasted at least 25 min after washout. Removal of the extracellular calcium decreased mEPSC frequency in both naïve and forskolin-treated slices. On the other hand, chelation of intracellular calcium by BAPTA-AM decreased mEPSC frequency in naïve, but not in forskolin-treated slices. A blockade of the calcium-sensing receptor (CaSR) resulted in an increase in mEPSC frequency in forskolin-treated, but not in naïve slices. These findings indicate that forskolin-induced potentiation is accompanied by changes in the mechanisms underlying Ca(2+)-dependent spontaneous release.